"Gus" is a common Greek American English translation of the name "Kostas", and "G" was a nickname given to him by a friend during his time living in the US.

The project was entitled Firewind, and was used as a showcase for Gus's guitar skills in an attempt to earn a professional recording deal.

The demo attracted the attention of Leviathan Records, but activity was put on hold when Gus was hired by Nightrage, Dream Evil, and Mystic Prophecy.

In July 2005, he temporarily replaced Christopher Amott as guitarist of melodic death metal band Arch Enemy on their Ozzfest dates, and also contributed to their album Doomsday Machine by playing lead guitar on the song "Taking Back my Soul".

Gus has also performed a few solos on the album Gallows Gallery by the Japanese avant-garde black metal band Sigh).

At the end of the world tour in December 2013, Firewind decided to go on an indefinite hiatus and Gus G launched his solo career with the release of his debut album, "I Am The Fire".

The album was released in March 2014 and features many guest musicians including Jacob Bunton Mats Levén, Jeff Scott Soto, Michael Starr of Steel Panther, Alexia Rodriguez of Eyes Set To Kill, Devour the Day and many more.

He toured in Europe extensively throughout 2014 together with Marty Friedman and in his native Greece with guitarist Uli Jon Roth.

[1] Once again, the album features collaborations with guests like Jacob Bunton Mats Leven, Elize Ryd of Amaranthe and Jeff Scott Soto.

If you listen to Uli Jon Roth, what he was doing back in the 70s with the Scorpions, and of course, with Electric Sun, you'll see, "Ohh, now I know where all the 80s shredders like Yngwie and all those guys got their inspiration from.

"'[7] Gus also cites Al Di Meola, Joe Stump, John Norum, Steve Vai, John Petrucci, Yngwie Malmsteen, George Lynch, Uli Jon Roth, Michael Schenker, Paul Gilbert, Marty Friedman, Jimi Hendrix, Jimmy Page, Gary Moore, The Beatles, The Doors, Black Sabbath, Metallica, Iron Maiden, Joe Satriani and many others as his influences.

[4] Firewind Solo releases Ozzy Osbourne Dream Evil Mystic Prophecy Nightrage Guest appearances

The 'FR' is featured along with the NT model in the video for "Falling to Pieces" and "Head Up High" and was discontinued in 2009 for North America, being replaced by the 'NT'.

In March 2010 ESP announced a new Gus G guitar the EC Revolver, it has a custom graphic finish, 22 frets, a 25.5-inch scale, and Seymour Duncan Blackouts active pickups.

[18] While playing with Ozzy Osbourne during the BlizzCon 2009 closing ceremony,[19] he could be seen playing two ESP Eclipse II guitars, one in Amber Cherry Sunburst tuned to Standard D, and another one in Vintage Black, tuned to Dropped C. In terms of picks and strings, he used Elixir Strings early in Firewind, then switched to DR, using 10-56.

Gus briefly had a signature Randall amp designed by him and based on the T2 head named Heaven and Hell.

2016 saw Gus G switching to Jackson Guitars shortly before heading out on his North American tour with Angel Vivaldi.